This report examines the question of trust fund adequacy in State Unemployment Insurance (UI). It is intended to provide both a general overview of UI trust fund management issues and specific observations on how the responsiveness of UI taxes affects the level of reserves needed by individual states. The discussion is initially presented at a general level and then in much more detail in later sections. The purposes of the report are to provide some tangible meaning to the term ?adequate trust fund reserves? and to provide a relatively simple method that states with positive trust fund balances can use to assess the adequacy of their reserves under current state law.